All week, we've been ranking Major League Baseball's top 10 teams in the four major areas. On Monday, it was the lineups. On Tuesday, the rotations. On Wednesday, the bullpens.

It's time for the always tall task of evaluating defense. To do so, we can consult any number of advanced metrics (I'm leaning heavily on Baseball Prospectus' team defensive efficiency rankings, Baseball Info Solutions' defensive runs saved and FanGraphs' Ultimate Zone Rating/150 games at each position from 2012), with the knowledge that each of them are flawed in their own ways and there's no be-all, end-all here. We're just trying to gauge which teams are in position to best turn balls in play into outs.

As we head into Spring Training, here are the top 10 defenses:

10. A's: Helped in part by the ample foul ground in their home park, the A's finished behind only to the Angels and Rays in turning balls in play into outs last season. There's no telling if they can repeat that. Right fielder Josh Reddick was one of the best defensive players in the Majors, with a 20.4 UZR/150 mark that trailed only that of Jason Heyward and Michael Bourn. Beyond that, though, it remains to be seen how Japanese import Hiroyuki Nakajima handles shortstop (reports on his defense are mixed), where and how often Jed Lowrie and Chris Young (both good defenders) play, etc. John Jaso is not a big plus behind the plate. Give credit where it's due, though, as Oakland had one of the more steady defenses in the game last year.

9. Orioles: The usual caveat about Gold Gloves: They can be the most misleading trophies in professional sports. But I'll nonetheless go ahead and note that center fielder Adam Jones, catcher Matt Wieters and shortstop J.J. Hardy each won one last year, giving the O's more Gold Glove representation than any other team. The metrics tell you that the award was more justifiable for Hardy and Wieters than it was for Jones. In any event, the O's ranked ninth in park-adjusted defensive efficiency (which no doubt helped them in all those close games they won), and they have upside as third baseman Manny Machado develops.

8. Braves: Atlanta topped all teams in Baseball Info Solutions' defensive runs saved count last season. Fans are understandably excited not just for what the Up-Up-Hey combo of Justin Upton, B.J. Upton and Jason Heyward can do at the plate but also what their speed and athleticism can accomplish in the field. It must be noted, though, that the Braves already had an outfield that rated among the best, with Michael Bourn on hand, and the advanced metrics were not especially kind in evaluating the defense of the two Uptons in 2012. In the infield, Andrelton Simmons should be an exceptional defender at shortstop, where he amassed a 31.6 UZR/150 mark in 426 innings in his rookie year. The Justin Upton trade did come at a cost, though, as the Braves lost Martin Prado's defensive skill set.

7. Padres: The Friars made 121 errors last season, the second-most in the big leagues. So what are they doing here? Well, they ranked third in park-adjusted defensive efficiency. Everth Cabrera and Chase Headley make for a real nice left side of the infield, and Cameron Maybin is an above-average center fielder. And though he will serve a 50-game suspension at the start of the season, Yasmani Grandal provides excellent defense behind the plate when he's back there.

6. Rangers: Though they made the fourth-fewest errors in baseball last season, the Rangers actually took a big step back in defensive efficiency rating from 2011 to '12. Part of the reason was a big regression in defensive runs saved and UZR/150 from Ian Kinsler at second base. But Kinsler has rated very well at the position in the past, and it is expected we'll see Jurickson Profar, another strong defender, slot into the middle infield more sooner than later. The primary point of emphasis with the Rangers is that they have one of the best left sides of the infield in the game, hands down, in Adrian Beltre and Elvis Andrus, and that goes a long way.

5. Giants: Go back and watch the film of the Giants' seven consecutive postseason victories, and beyond the sterling performances of the starters, what will strike you is the dynamic defensive play that led them to baseball's Promised Land. Shortstop Brandon Crawford and left fielder Gregor Blanco were particularly sensational. The Giants generally do right by their pitchers and had a defensive unit that ranked 12th in park-adjusted efficiency, with catcher Buster Posey, first baseman Brandon Belt and third baseman Pablo Sandoval all pluses at their positions. They're not perfect (witness Hunter Pence's acrobatics in the outfield), but they get the job done.

4. Nationals: The Nats, who find themselves in good standing on all of these lists, ranked fifth in defensive efficiency and seventh in defensive runs saved last season. Most important, they've improved their defensive outlook with the addition of center fielder Denard Span, who will allow Bryce Harper to shift to left. Washington also expects to have more stability behind the plate, where Kurt Suzuki is a well-regarded defender. So one of the better defensive alignments in 2012 could be even better.

3. Reds: The Reds registered the fifth-highest number of defensive runs saved in the Majors last season. The key was being strong up the middle, as second baseman Brandon Phillips, shortstop Zack Cozart and catcher Ryan Hanigan each ranked among the best at his position in DRS. This was especially impressive for Cozart, who made an instant impact in his rookie year. The Reds also had pitchers who fielded well, saving more defensive runs than any other staff in the game. The big question for the Reds is how well Shin-Soo Choo, who had an uncharacteristically miserable defensive season with the Indians, will transition to center field, where he's barely played in the big leagues. In a free-agent walk year, Choo might be tentative in his outfield play.

2. Rays: Every season is full of strange stats, and here's one from 2012: The Rays committed the fifth-most errors, with 114. That's totally against the grain for the Rays. Next you'll tell me they gave somebody a $100 million contract. (What? They did that too?) Of course, the inordinately high error count is attributable, in large measure, to injuries and guys playing out of position. Having that $100 million man, Evan Longoria, at third base for a full season would go a long way toward the Rays reclaiming their status as having one of the most reliable defenses in the game, and having Yunel Escobar at short (instead of Ben Zobrist, who can go back to roaming) will be a huge boost, too. The thing is, for all those errors, the Rays still ranked No. 1 on Baseball Prospectus' park-adjusted defensive efficiency scale. In 2013, I firmly expect them to be the elite defensive unit we've generally known them to be.

1. Angels: Tigers manager Jim Leyland summed it up best last September: "The best defensive team I've seen is the Angels. We couldn't get a ground ball through the infield, couldn't get a fly ball to fall in the grass and we had one taken away that was over the fence. How are you going to beat that?" The Angels were even with the Rays atop BP's defensive efficiency scale, and they rated third on BIS' defensive runs saved above average tally. But it should be noted that while Josh Hamilton's arrival helps the offense, his defensive metrics in the outfield plunged last season. His -15.5 UZR/150 mark was among the worst in the game. So right field will look dramatically different with Torii Hunter out of the picture. The rest of the Angels' outfield, however, will be electric with Peter Bourjos in center and Mike Trout in left, and the Angels remain strong in the infield -- a big key, considering the concerns about their pitching staff.

Honorable mention: The Mariners have consistently been among the best defensive teams during Jack Zduriencik's time as general manager, but they clearly sacrificed some defense in their pursuit of offensive upgrades this offseason. It's worth noting, though, that Brendan Ryan and Dustin Ackley were credited with more defensive runs saved than any other keystone combo in the game last year. ... Shortstop Clint Barmes didn't hit a lick, but he did help guide the Pirates to new heights on the defensive scale in 2012. And Russell Martin is a strong addition behind the plate. ... The Dodgers had a top-10 defense last year, but you really have to worry about Hanley Ramirez playing shortstop, which is the plan for now. ... The White Sox, who made the fewest errors in baseball last season, improved considerably, thanks in large measure to Alex Rios' move from center to right field. ... The Blue Jays led the American League in defensive runs saved but probably won't fare nearly as well with Jose Reyes in place of Escobar at short, Emilio Bonifacio in place of Kelly Johnson at second and Melky Cabrera in the outfield. ... I had the Royals at No. 10 on this list last year. They proceeded to finish with metrics that rated them anywhere from below average to awful, which shows how much I know. But there is still a lot of youth and athleticism on their roster with the potential to evolve into an above-average unit.

Anthony Castrovince is a reporter for MLB.com. Read his columns and follow him on Twitter at @Castrovince. Matthew Leach contributed to this story. This story was not subject to the approval of Major League Baseball or its clubs.